It has been well-known to add glass fibers to a thermoplastic resin in order to reinforce a formed article produced by forming the thermoplastic resin. In particular, it has been known to use glass fibers that have been surface-treated using an organosilane compound or the like when preparing a composition that includes a polyolefin and glass fibers in order to improve the dispersibility of the glass fibers in the polyolefin as well as the affinity of the glass fibers to the polyolefin. A sufficient improvement in strength cannot be achieved when glass fibers are added to crystalline polypropylene. Patent Document 1 proposes using a modified polypropylene instead of crystalline polypropylene in order to achieve a sufficient improvement in strength, the modified polypropylene being obtained by modifying a crystallinity ethylene-propylene block polymer using an organosilane compound (that includes an ethylenically unsaturated bond) and an organic peroxide. Patent Document 2 proposes a modified polyolefin as a modifier when adding glass fibers to a polyolefin, the modified polyolefin being obtained by melt-mixing polypropylene, an unsaturated carboxylic acid, and an organic peroxide, and heating the mixture.
Patent Document 3 discloses that a high-frequency connector insulating member that exhibits excellent high-frequency electrical properties and excellent formability while preventing a situation in which cracks occur in a resin part can be obtained by utilizing a resin composition prepared by adding a filler and a soft polymer to an alicyclic structure-containing polymer resin (e.g., norbornene-based resin). Patent Document 4 discloses that a thermoplastic norbornene-based resin composition in which a filler and a resin matrix exhibit good adhesion can be obtained by utilizing an unsaturated carboxylic acid-modified elastomer as a soft polymer.
Patent Document 5 discloses that an insulating material that exhibits excellent oxidation resistance and excellent heat resistance while maintaining high heat resistance, low hygroscopicity, and electrical insulating properties can be obtained by utilizing a cycloolefin-based resin that includes a carboxylic acid derivative residue. Patent Document 6 discloses that electrical properties (e.g., dielectric constant) and copper foil peel strength are improved, and an additive can be uniformly dispersed when a modified norbornene-based polymer is used as a circuit board resin material, the modified norbornene-based polymer being obtained by subjecting an aromatic ring-containing norbornene-based polymer to graft modification using an unsaturated epoxy compound, an unsaturated carboxylic acid compound, or the like.
An alicyclic structure-containing polymer obtained by polymerizing a norbornene-based monomer is an amorphous resin that does not have a melting point when produced using a normal method. It has been known that a crystalline resin having a melting point can be obtained by subjecting dicyclopentadiene to ring-opening polymerization using a specific catalyst, and hydrogenating the carbon-carbon double bond included in the resulting ring-opening polymer. Patent Document 7 discloses that a hydrogenated crystalline dicyclopentadiene ring-opening polymer can produce a film that exhibits excellent heat resistance and flatness, and can be used in various fields.